In accordance with the structure and property of an electromagnetic spectrum, the infrared information of a target refers to the difference between the target and the background in terms of radiation, reflection, and scattering characteristics acquired by an infrared spectral band sensor, which includes radiation, reflection, and scattering characteristics of each fine spectrum (line) band of short-wave, medium-wave, and long-wave infrared. Compared with the target/background information of a single spectral band, the information of multiple fine spectral bands can represent more comprehensively and accurately the characteristics inherent in the target and the background. A conventional detection method generally uses a single spectral band imaging and detecting method to collect the energy of the target/background on a wide spectral band. At this time, this target is often drowned in a complex background clutter or interfered, the signal is very weak, and the signal to noise ratio and the signal to clutter ratio are very low.
An image-spectrum associated device combines the infrared spectrum of the target and infrared imaging information, and by utilizing a unique spectrum feature of the target on a spectral line of the infrared spectrum, the detectability of the target can be greatly enhanced. The technology has been widely applied in the field of remote sensing for studying the spectrum features of various targets and backgrounds, thereby providing a data basis for the classification and monitoring of scenes, as well as the detection and identification of the target.
Great importance has been attached to the study and development of such an image-spectrum associated device around the world. At present, the commonly used image-spectrum associated device is an imaging spectrometer. This type of imaging spectrometer is usually installed on an aircraft, of which a scanning rotating mirror rotates, such that the received instantaneous field of view moves perpendicular to the flight direction, thereby realizing the scanning. Along with the forward movement of the aircraft, the imaging spectrometer completes the two-dimensional scanning, ground object scenes are scanned point by point, and point-by-point measurement is performed at individual wavebands, so that multi-spectrum remote sensing image information is obtained. For example, the AVIPIS system completed by the American JPL Lab, the GERIS system of the American GER company, and the PHI push-broom imaging spectrometer system studied by Shanghai Institute of Technical Physics of Chinese Academy of Sciences. This type of system can provide abundant two-dimensional space information and third-dimensional spectrum data, that is, the spectrum information can be extracted at each point of the two-dimensional space imaging. However, this type of device extracts image cube data of a target scene, which has a very large information processing amount and a low spatial resolution, is suitable for measuring a stationary target but uneasy to cope with a moving target, and has a high price which can be hardly accepted by users.
In many practical applications, it is unnecessary to acquire spectrums of stationary ground objects and sky background in real time, while spectral characteristics needs to be utilized to automatically perform detecting identification and exploring identification in real time on a moving target (a time-varying object) or a local region in the scene, such as an aircraft in the air, a ship on the sea, a moving vehicle, fire, or explosion.
In the relevant patents, “Image-spectrum integrated Method and Device for Acquisition of Spectrum Information of Time-varying Object” (ZL200910272679.9) and “Multi-waveband Spectral Characteristic Detection Identification Method and Device for Moving Object” (ZL201110430969.9) applied by Huazhong University of Science and Technology in China, which have been authorized, adopt a mode of combining two lenses to realize image spectrum association, which has a large device volume; a planar infrared window is adopted, which has a small field of view; and the measurement method is directed to a single moving target, which has no intelligent automatic control strategy to guide the process of remote sensing measurement.
With respect to the above automatic detection and spectrum identification on multiple moving targets and time-varying objects, the spectrum imaging device commonly used recently has the following disadvantages: (1) being not applicable to the spectrum measurement in a local region in a scene; (2) failing to realize the automatic tracking spectrum measurement on multiple moving targets; (3) being unable to perform online processing and identification on the target spectrum; and (4) having a large data processing amount, a low speed, and a high price.